Data center virtualization technologies are now well adopted into information technology infrastructures. As more and more applications are deployed in a virtualized infrastructure, there is a growing need for recovery mechanisms to support mission critical application deployment, while providing complete business continuity and disaster recovery.
Virtual servers are logical entities that run as software in a server virtualization infrastructure, referred to as a “hypervisor”. Examples of hypervisors are VMWARE® ESX manufactured by VMware, Inc. of Palo Alto, Calif., HyperV manufactured by Microsoft Corporation of Redmond, Wash., XENSERVER® manufactured by Citrix Systems, Inc. of Fort Lauderdale, Fla., Redhat KVM manufactured by Redhat, Inc. of Raleigh, N.C., and Oracle VM manufactured by Oracle Corporation of Redwood Shores, Calif. A hypervisor provides storage device emulation, referred to as “virtual disks”, to virtual servers. Hypervisor implements virtual disks using back-end technologies such as files on a dedicated file system, or raw mapping to physical devices.
As distinct from physical servers that run on hardware, virtual servers run their operating systems within an emulation layer that is provided by a hypervisor. Although virtual servers are software, nevertheless they perform the same tasks as physical servers, including running server applications such as database applications, customer relation management applications and MICROSOFT EXCHANGE SERVER®. Most applications that run on physical servers are portable to run on virtual servers. As distinct from virtual desktops that run client side applications and service individual users, virtual servers run applications that service a large number of clients.
As such, virtual servers depend critically on data services for their availability, security, mobility and compliance requirements. Data services include inter alia continuous data protection, disaster recovery, remote replication, data security, mobility, and data retention and archiving policies.
Conventional replication and disaster recovery systems were not designed to deal with the demands created by the virtualization paradigm. Most conventional replication systems are not implemented at the hypervisor level, with the virtual servers and virtual disks, but instead are implemented at the physical disk level. As such, these conventional systems are not fully virtualization-aware. In turn, the lack of virtualization awareness creates an operational and administrative burden, and a certain degree of inflexibility.
It would thus be of advantage to have data services that are fully virtualization-aware.